As known in the art, aerial or satellite photographs refer to any photographs of the ground or objects taken from any one elevated position in the air and include air photographs of the ground taken from an aircraft or the like in flight and artificial satellite photographs of the ground taken from the air by artificial satellites.
The aerial or satellite photographs may be categorized into vertical photographs and oblique photographs. The vertical photographs may be used in areas of expertise such as a photo survey, photo-interpretation, topographic map manufacture, etc., and the oblique photographs may be used for a news photo, aerial view, etc.
On the other hand, typical navigation systems mounted on, e.g., a vehicle or a smart phone, capture their current locations based on location information of the vehicles received through GPS (Global Positioning System) satellites, read data of a current location from a road database which is built in the navigation systems or received from the outside, and display a currently driving road together with the location of the vehicles, thereby helping a driver to identify the location of the road or to find a destination with ease when driving on the first trip.
In order to satisfy user needs, recently, a navigation system provides to a user more precise route information through advanced technologies, which are integrated into the navigation system, such as informing expected arrival time from a starting point to a destination and suggesting a detour depending on a road situation to the destination, when the user sets the destination.
Moreover, in recent years, other technologies have been studied and developed to display a currently driving location of a vehicle on an image of an aerial or satellite photograph instead of a road map derived from a road map database and guide a more realistic route to a driver.
However, such a technology had been developed up to a just level that aerial or satellite photographs are continually received and the position of the vehicle is displayed on an image of the received aerial or satellite photograph. If there is a shadow cast by a structure such as a building in an aerial or satellite photograph when the aerial or satellite photograph is acquired, a driver has to identify his/her route from the image of the aerial or satellite photograph with the shadow, which results in deteriorating the visibility of the driver.
Related art of the disclosure of the present invention is disclosed in Korean Laid-Open patent No. 10-2012-0086892, entitled “SYSTEM AND METHOD FOR WARNING A LANE DEPARTURE OF A VEHICLE NAVIGATION DEVICE,” published on Aug. 6, 2012, which is incorporated by reference herein in its entirety.